The World Wide Web is a hypertext based Internet information service. The idea behind the hypertext is that instead of reading text in a rigid linear structure (such as a book), a user can skip from one point to another. It is possible to get more information on the topic, go back, jump to other topics, and navigate through the text.
Information takes up a great deal of space, particularly when it includes images and multimedia capabilities. The Web is successful in providing so much information because that information is distributed globally across thousands of Web sites, each of which contributes the space for the information it publishes.
One distinctive feature of the Web is that it is interactive. Interactivity is the ability to "talk back" to the Web server. More traditional media such as television are not interactive at all. Other than changing a channel the viewer has little control over the content. The Web is inherently interactive: the act of selecting a link and jumping to another Web page to go somewhere else on the Web is a form of interactivity. In addition to this simple interactivity, however, pages can be designed to contain interactive forms that readers can fill out. Forms can contain text-entry areas, radio buttons, or simple menus of items. When the form is submitted, the information readers type is sent back to the server where pages originated. Despite this interactivity, however, users are still unable to limit the stream of information they are getting to the information they actually want to see.
One of the biggest problems people encounter when they explore the Web is finding information they are particularly looking for. Many Web sites providing a huge number of bytes of information are now equipped with global search engines, which search through the content of various databases looking for words that match user's query. However, this method produces a large number of irrelevant results. Consequently, the user spends a lot of time sorting through the data looking for the desired information.
Such time consuming process is especially undesirable when the searcher is looking for health related information. There are many web sites that offer information about new developments in medicine and health. It is also especially important for this type of information to be tailored to the specific needs of individual users. However, at the present time there is no efficient way of searching for specific information that the user needs or desires.